Description: (Taken directly from the application) The overall objective of the Animal Core is to provide program project investigators with the ability to utilize animal models in the execution of their proposed research projects, as well as establish new animal models for the investigation of the mechanisms involved in the regulation of organogenesis by orphan nuclear receptors. Although the use of mouse models provides an invaluable source of reagents for investigating regulatory mechanisms in vivo, in a physiologically regulated system, the use of mice in biomedical research is costly with respect to equipment, animal resources, and technical expertise. The Animal Core will serve as a resource for the execution and training in the use of all animal manipulations needed in this program project application. The Animal Core will minimize the cost of utilizing animal models in this program project by consolidating the equipment, expertise, and animal resources. This will ensure an efficient use of animal research at minimal cost.